Electric mathematical educational appliance



Nov. 20, 1945. A. H. THOMAS ELECTRIC MATHEMATICAL EDUCATIONAL APPLIANCE Filed Feb. 19, 1944 4 Sheets-Sheet 1 v mm Inventor Noy. 20, 1945. A. H. THOMAS ELEC TRI C MATHEMAT I CAL EDUCA'I IONAL APPLI ANCE 4 Sheets-Shed 2 Inventor Filed Feb. 19, 1944 .1220): H. mamas By WW 3m Nov. 20, 1945. A. H. THOMAS ELECTRIC MATHEMATICAL EDUCATIONAL APPLIANCE 4 Sheets-Sheet 3 Filed Feb. 19, 1944 Attorneys Nov. 20, 1945. A. H. THOMAS 2,389,394

ELECTRIC MATHEMATICAL EDUCATIONAL APPLIANCE Filed Feb. 19, 1944 4 Sheets-Sheet 4 Inventor Jdiezn 155 ffiaazaaa Patented Nov. 20, 1945 ELECTRIC MATHEMATICAL EDUCATIONAL V APPLIANCE Allan H.-Thomas, Butte, Mont., assignor of onehalf to Joseph L. Lenz, Butta: Mont.

Application February 19, 1944. Serial No. 523,141

(Cl. 35-48) V 2 Claims.

invention relates to improvements in educational apnliances which are. of assistance in. teaching students and it has for its principal object an electrically operated teaching aid. for teaching the use of measuring instruments or appliances employing scales sub-divided in fractions such as a rule showing length units subdivided into fractional units.

To acquaint the student with the numerical values represented bythc divisions and sub-divisions of a rule or of scales or of .instrument carrying scales, to help in finding the location of a division corresponding to a numerical value, to test the correctness of. simple operations such as additions 01. fractions and for similar purposes, a rule showing the division into inches and fractions of inches is provided. in which every division mark or a selected number of division marks is equipped with electric contacts. These contacts are connectedwith an adjustable test switch, with an indicator and with a testcontact; the test switch maybe set in such a way that the indicator shows the indication correct. for this mark when the contact allocated to the mark representing the correct result is touched by the test contact, and it. shows the indication incorrect or false when a contact associated with any other mark on the rule is touched.

Educational amusement and test apparatus of the samageneral type attempting to instruct or amuse children or to. supply vpsycholo ical or ability tests have been proposed in various forms; but their functions are more or less performed by establishing a fixed connection between contacts to be tested and allotted to a question and other contacts allotted to the answer. The question is usually brought into some kind of relation to one of a series of contacts. tobe tested by means of cards, strips or sheets carrying a printed text. or provided with pictures or marks or the like; an s mil rv each of a ser es of" n wers i brou ht into some. r lation w th on f a seri s of contacts which may be arranged either in rows, in squares or in' a circle around a rotating switch. When the contact related to the right answer is touched, a signal of some kind indicating that the answer was correct is given.

When psychological or ability tests are made, contacts to be tested are provided with a variety of signals so that the ability or psychological condition can be judged by the frequency or nature of the signal.

Ed cational apparatus. o this type are merely useful for children below the grade school For on account of the. fixed Connection betwee the contacts allotted to the question and to the answer students above grade, s hool aeel wou consciously or unconsciously quickly .rnemorize the relative. location of the contacts and the educational value would, therefore, be very small. or

' nil. This drawback would still subsist if an tempt were made to change the. connections occasionally. J

The educational appliance according to the p ent invention permits to give answers to questions individually as there is no mechanical or fixed relation. between question and answer. The answer for the individual question has-to be supplied either by the teacher or by the student himself or by usin a system of. correspond n between marks when ad usting the adjustable switch. The adjustment of the apparatusi'n accordance with the correct answer has therefore to be made before the correctness of the answer given by the student can be tested and in this respect the invention difiers basically from'the appliances heretofore proposed. Theeducational value. of such ail appliance is, much greater than. that of oral teaching on account of the participation of the pupil who, in the event that more elementary problems such as naming the numerical value of the division marks pointed out to him or of locating a given division mark may supply the answer .himself by adjusting the test switch in accordance with the mark. The means for obtaining this result. consists mainly in the connection of. each contactallotted to a graduation mark with two series of contacts one test switch. One series of. contacts on said switch is permanently connected with contacts. of the graduation marks to be tested and. to the signal incorrect. The otherseries of contacts of the switch is connected with the indicator. give ing the signal "correct-.7 andone of them is connected with an individual contact of thegradua. tion scale by the adjustment of the test switch. This adjustment also disconnects the correspond.- ing contact of the first-named series the graduation mark. contacts. Thus, after adjusting the test switch in accordance with the answer corresponding to the questions one and. only one contact associated with the graduation. marks will be singled out asfurnishing theanswer correct. The insertion of the. test plug. into the socket of any one of the other. graduation mark ontacts will. actuate the signal incorrect.

t is se n that no permanent connection exists between the graduation marks and the indicator.

Each graduation mark contact may be connected with the indicator notifying the student that his answer is correct and the selection is solely determined by the adjustment of the test switch.

Other objects and advantages of the invention will become apparent to the reader of the following description.

Figure 1 represents a front elevational viewof the device.

Figure 2 is an end elevational view.

Figure 3 is a vertical sectional view.v through the selector. s

Figure 4 is a front elevational view of theselector. Figure 5 is a vertical sectional view-f through the selector. 1

,to include as many fractional markings as there are. units.

Figure 6 is a vertical secretariat throug the selector showing the ball contacts. .Eigure 7 isan enlarged detailed sectional view showing one of the ball contacts in contact with the. opposedring. v

s Fi ure. 8 is fa. vertical thelarnpibox.

Figure 9. isacross. sectional view through the Figure 10 electrical connections between the devices involved.

.Figure 11 is a fragmentary perspective and exploded view showing theshaftofthe selector (see Figure3) Referring vtothe example illustrated in the drawings. wherein like numerals [designate like partanumeral 5, denotesanelongated rule, which forclassroom use will. be say, .six feet long. each foot, representing one. inch. I u

Mounted'injuxtaposition with respect to the rule Sis ailamp, box generally referred to by numeral .6 and further in juxtaposition with respect to the rule 5 isa selector or test switch generally referred to by numeral] and a test contact 39 sectional view through electrical connected by acable 38 to the transformer box 31a; ofa transformer 31 (shown in Figure 10) connecting the arrangement. with the mains.

The rule ,5. isfllaid off in sixteenths of an inch orin smaller-or larger divisions of fractions, if desired, and at each graduat ion, the rule has an opening or aperture 52 in which is disposed a tube 8 of .c urrent conductivematerial. A conduit 9 extends along the rear side of the rule 5 and this conduit houses a multic onduc tor cable 55' containing insulatedstrands or conductors each of whichis ,connected withxone of the tubular contactsB; l 'lsexpleined later corresponding. contacts belq l i g .to the same unit fractionsin the various units may'beconnected with the same strand or conductor. to reduce the number ofconductors in h cab a Thelarnp boxfi consists ,ofa case lllhaving a window If at the front side thereof and this case i i10 is dividedbyan internal horizontal partition divid ethe nte or-sinful ppe and lower lamp; compartments l3,7[4, respectively. (Figures 1 and 8) containing bulbs 15,. I6 of different colorsi, the upper bulbjibeing for instance red while the lower bulb. [Bis white; Words such as true" and false' arepreferably located on the inner sides of .the upper and lower portions of the pane if, covering the compartments I3 and I 4. The panel I is pre ferablyfrosted or otherwise made translucent; so that when one orv the other of the two bulbs. is lighted this word willbecome visible.

isadiagraniimatic view showing the plastics or the like.

, -The annular partition wall 28 carries a single annular contact plate 2? on its inner side facing the partition 23, while the latter, carries two series of concentric contacts. V'lI'he inner series consists of contacts 32 formed by boltsor rivets firmly secured in the partition walls. Each contact cor responds to fone of the fractional units. The outer series comprises similar contacts, each preferably arranged in radial alignment with one of the inner contacts 32 and each consisting of a metal'cup or. cup-shaped'socket 24 from which a contact, ball 26 projects. Said ball is urged towards thefront 'end by a compression spring 25 pressing against theclosed" end of the cup-shapedjs'ocketid. Thecups fliface the annular metalf plate 27, so that normally the ball 25 is pressed againstsaid plate and establishes con- [Cooperating :with the two series of contacts are two arms 3 I and 33 rotatablygarranged on a shaft [9. Saidshaft provided at itsrear end with a head22 against which a spring 36 is pressing. Thejspring finds its support in a recess 35 of the partition wall 23.; The spring urgestl'ie shaft 19 and the arms 3l' an'd 33 mounted on it towards thepartitionwall. u

The said shaft carries two blocks 29, 3 0 of insulating material upon which the arms 3'! 33am mounted; I'I he' arm, 3lwhich is ofthe usual contactor arm: type is mounted on the front end, of block 30. Thisoontactor arm cooperates with'the inner series o'f contacts 32 and it is held inconductive' engagement with an annular disk l9a surrounding the shaft [9 and fixed on thepartition w'a'll23; As the contactor arm 3!, mounted on block3ll carried by the ,shaftlS is'urged towards the partition wall by spring 36, the metallic central part'of the arm is pressed against disk Na and is, therefore, capable of establishing contact with saiddisk. u

The second arm 33, althoughhaving the appearance of a-contactor arm'is not a contact making arm. -It is'ins'ulatd from shaft [9 and the other arm 3| 'by'the'blocks 29,30 between which it is mounted. It consists of a metallic arm which carries on its'rear face an" insulatingpiece' 34. When turned to a'specific contact 24, it will press back the? wall-26-and interpose itself between. it and the annular contact?! and by means of the insulating piece 34 will separate the ball 25 of the contact 34; on which itrests from the said annular contact 21;, H g

'As both arms 3! and 33 move-together by virtue of their being mounted on the insulated blocks 29, 30 carried by the shaft Lamp 31 when set on a specific contact of the series will establish contact with one of the contacts 32 of the inner seri es while the arm 33'will' interrupt contact of the corresponding contact 2410f the outer series withthe annularjdisc 21; c

' The shaft 19 protrudes from the casing passing through a hole in the'cover plate I8 and on this protruding part carries a knob 2| fixed on the shaft by means of apin 20 passing through a hole 20a ofthe shaft. The said knob carries a pointer or indicator 5| running over the marks on the cover plate permitting to adjust the knob and with it the shaft and the parts. carried by it in the desired manner.

Electrical connections are made as will be more fully explained with the disk IQa, connected with a conductor 4|. Each of the contacts of the series 24, 26 or 32 is connected with one of the conductors 42 and between corresponding contacts of the two series are conductors 43. Moreover, the annular disk 21 is connected with a conductor 40.

As will be seen from Figure 10, each socket 8 in the apertures 50 associated with one of the inch fractions is connected by means of a conductor 42 of the multi-conductor cable with one of the ball contacts 26 of the outer series and, by means of the conductors 43, with the corresponding contacts 32 of the inner series. The annular disk 2'! against which all the contact balls 26 are pressed with the exception of the one resting against arm 33, is connected by means of conductor 40 with the red light indicating the false answer.

Contact disk l9a, however, which establishes contact with arm 3| is connected with conductor 4| containing the white light (indicating a correct answer). Both branches 40 and 4| may join of the student is desired the adjustment "of the and are connected with the secondary of a bell or step down transformer 31, which is enclosed in the casing 31a. The other end of the secondary is connected with the test plug 39 or test contact. The primary of the transformer is connected with the power mains as usual.

From Figure 10 it is apparent that the contact allotted to the successive inches and fractions of inches are connected in series with the sockets of the other inches or fractions of inches.

This series connection is made in the modification shown merely because the separate connection of each graduation mark for each fraction of an inch, even if the inch is divided merely into one-sixteenth inch fractions would entail a large number of contacts and conductors. It has been found by experience that errors as regards the numerical value of an inch mark are very rare or practically do not occur at all especially if the numerical values of the inches are plainly written on the scale of the rule. Errors of this type, if occurring, are easily corrected by the teacher or the student so that the small disadvantage due to the failure of the indicator to indicate the inch value canbe tolerated in view of the greater economy obtained by the reduction of conductors and contacts. Jumpers 42 extend from each of the sockets 8 to the corresponding ball contacts 26 and also to the corresponding contacts 32 by short jumpers 43.

The operation of the device is the following:

Assuming that the apparatus is used to train the student in the immediate recognition of the fraction mark to which the teacher is pointing or in finding a fraction mark on the rule the numerical value of which is mentioned by the teacher, the teacher may set the pointer 5| of the test switch 1 to the mark which he wants to be pointed out by the student. If the cooperation sviritch 1 may 'be'left to the student hiinself and is performed after the answer has been given.

When the "student approaches the rule 5 with the test contact 39*and inserts this in the proper contact tube 8, current will flow through the transformer 31 and contact plug, tube contact 8 and the corresponding jumper 42 to the proper ball contact 26 but cannot reach the ring 21 because of the interposition of the piece of insulation 34 carried by the contactor 33, current will flow however, to the contact 32 allotted to the graduation mark into which the test contact was inserted and the contact 3| will carry the current to the conductor ll and from there by way of the white lamp US to the other side of the secondary of the transformer.

However, had the student made the wrong selection by inserting the answer pin 29 in, for instance, any one of the adjacent fraction sockets. the current would flow from the ball contact 26 to the ring 21 and from there to the red lamp l5, due to the fact that the ball contacts are engaged with the ring 21 so that the selection of any one of these will close the circuit of the lamp 5 and will be indicated by the signal false.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size and materials may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter.

Having described the invention, what is claimed as new is:

1. A didactic measuring apparatus for training persons in the use of measuring systems comprising a rule provided with graduation marks indicating several length units and small fractions of said units, each graduation mark being provided with a contact, and corresponding fractional contacts in successive units being connected with each other, a switch provided with two rows of contacts, each contact of a row being connected with one of the graduation mark con- 7 tacts, two indicator signals arranged in different circuits and a test contact arranged in a branch common to both aforesaid circuits said test contact being manipulated by the person using the apparatus and adapted to be brought into operative connection with the graduation mark contacts, a manually operated sliding means on said switch, said switch being provided with means for closing all the circuits connected with one indicator signal over any one of the connections between switch contacts and graduation marks but one, when the test contact is operated, and further provided with means for opening all the circuits through the other indication signal while at the same time closing the circuit of one contact and graduation mark through said signal.

2. A didactic measuring apparatus for training persons in the use of measuring systems comprising a rule provided with graduation marks indicating several length units and small fractions of said units, each graduation mark being provided with a contact, and corresponding fractional contacts in successive units being connected with each other, a switch provided with two rows of contacts, each contact of a row being connected with one of the graduation mark contacts, two indicator signals arranged in different circuits and a test contact arranged in a branch common to both aforesaid circuits, said test contact being manipulated by the person using the apparatus and adapted 'to-bebrought into operative connection with the graduation mark-contacts, a manually operated sliding means on said switch, comprising an insulating and a conducting;member in contact with all the contacts of 5 one row; the insulating member sliding between said contact vmember and the individual cont acts, and adapted to separate one contact at a ALLAN H. THOMAS. 

